This invention relates to a piling method in which a pile or an equivalent being below an apparatus is moved mainly downwards by means of a movable part inside the apparatus. Furthermore, the invention relates to a piling apparatus which includes a body and a part movable inside the body.
Piling methods and apparatuses are utilised in embedding piles, columns or equivalents which are used e.g. to reinforce building foundations or to reinforce, support or compact ground.
Known apparatuses commonly include a part movable in the vertical direction i.e. upwards and downwards i.e. a hammer ram and a separate cushion block to be located on top of the pile. When driving the pile, the movable part i.e. hammer ram is above the pile, the movable part i.e. hammer ram is moved in the vertical direction and it is hit onto the freely moving cushion block located at the upper end of the pile. Then, the pile is pushed downwards. The cushion block decreases the stress applied to the pile. Often, there is between the pile and the cushion block other material which dampens and softens the hit. This causes the weakening of piling efficiency and the breaking of the pile and the cushion block.
Disadvantages are related to the use of known apparatuses. When the hammer ram hits the cushion block and the cushion block hits the pile, a powerful hitting noise is created. Piling is very noisy work, which must be considered when designing working sites and working hours. When using cushion blocks and other damping materials, part of work efficiency is lost when the hit of the hammer ram is dampened when striking the cushion block. Furthermore, cushion blocks and other damping materials are parts which wear and which have to be replaced from time to time, whereby work must be interrupted. A problem of the use of cushion blocks and other softening materials is also that their properties change as they wear, whereby the exact monitoring of the hit event is difficult.
The properties and quality of the ground to be piled vary considerably due to different soils. This is worth considering when driving piles.
When handling steel piles and sheet piles, the work often requires pulling them upwards in some stage. Pulling sheet piles up is recently done by vibrating, which sets off the disturbance of the soil in the working area, which further makes working awkward. There also occur problems when pulling the protection pipes of cast-in-place piles up. After the cast-in-place pile has been cast inside the protection pipe hit into the ground, the protection pipe is pulled off. There exists no suitable method for this. When a vibrator is used in pulling up, the surrounding ground is disturbed and the carrying capacity of the pile is weakened as the ground properties change.
An object of the invention is to disclose a piling method and apparatus which eliminate disadvantages related to recent piling methods and apparatuses. A particular object of the invention is to introduce a piling method and apparatus which provide effective, cost-efficient and noiseless piling. A further object of the invention is to disclose a piling method and apparatus which provide a jerky motion.